SR - good suggestion that a proper court would be the venue of choice where CASA is forced to explain itself in the real world. However, the issue may well be that the only avenue is indeed through the AAT.
I won't repeat the Avalon DCA HS125 Captain's name here, but his surname thereafter was preceded by "wheels up......"
The crew did indeed return to the aircraft cabin after the event, and that generated the mystery as to why the gear was found by the investigators to be in the down position. Astute readers will probably work out that there is only one reason that the gear handle was found in this position.